Common Tern

Blue ring with a white 3-alpha code.

note 1 : all birds are ringed as pulli and have the c-ring on their left tarsus and a metal ring on the right.

note 2 : used codes are : PAA-PZZ

note 3 : used letters are : A, C, E, F, H, J, K, L, N, P, R, S, T, U, V, X, Y, Z.

note 4 : birds ringed since 2015 from Dublin Port (Ireland) breeding colony.

note 5 : 

White ring with a black three alpha code.

note 1 : used codes are JAA-JZZ.

note 2 :  

White ring with a 3 alpha-numeric code (starting letter 'L') (on left tarsus) (to be read from bottom to top) and metal ring (on right tarsus).

note 1 : starting letter is with LHn and LWn (where n = number). These rings were used in on roof-top colony in Leeuwarden in 2014 for nestlings.

note 2 : some birds -starting letter 'L' are ringed belong the eastern part of the river the Maas in the Netherlands and the used codes are : L3x, L4x, L5x, L7x, L8x, L9x and L01 untill L99 (where 'x' is a letter). 

note 3 : used letters are A, C, E, F, H, J, K, L, N, P, S, T, U, V, X Y, Z.

note 4 : 

Blue ring with a white two alpha code (on one leg) and metal ring (on right leg).

note 1 : used codes are VA-VZ and KA-KZ.

note 2 : these rings were fitted on nestlings in Delfzijl since 2014.

note 3 : 

Green ring with a white two alpha code and metal ring (on other leg).

note 1 : used letters are: A, C, F, H, J, L, M, N, P, R, T, U, V, W and X.

note 2 : birds ringed since 2010.

note 3 :

Green ring with a white two alpha-numeric code and metal ring (on other leg).

note 1 : used letters are: A, C, F, H, J, L, M, N, P, R, T, U, V, W and X.

note 2 : used numbers are 0 - 9.

note 3 : birds ringed since 2010.

note 4 :

White ring with a black three alpha-numeric code.

note 1 : letter 'V' on first, second or third position.

note 2 : birds ringed since spring 2014 on Griend, The Netherlands.

note 3 :  

Dark-green ring with a white 2 numeric code.

note 1 : this projects is illegaly started in Spain !!

note 2 : this project is not in use.

note 3 : used codes : 00 - 39.

note 4 : used alpha-numeric codes : 0A - 3X.

note 5 : 

Yellow flag with a black two alpha code (on left tarsus) and metal ring (on right tarsus).

note 1 : birds ringed in the UK, North Wales.

note 2 : 

White ring with a black three alpha code, starting letter 'B' (on left leg) and metal ring (on right leg).

note 1 :